402 STUDIES IN GENERAL PHYSIOLOGY 



or whether the altered metabolism in the initial lack of 

 oxygen does not at first lead to a slight acceleration of 

 cleavage. If the latter were correct, it would give a basis 

 for the explanation of a very purposeful arrangement in 

 organic nature, namely, the increase in respiratory activity 

 in the lack of oxygen. For if lack of oxygen leads to such 

 a universal change in metabolism that more energy is at first 

 set free than under normal conditions, then the purposeful 

 arrangement of the respiratory center is only a special case 

 of a general property of protoplasm. 



Yet the acceleration of cleavage in the Engelmann 

 chamber might also be dependent upon an increase in 

 temperature. One source of this increase in temperature 

 might be sought in these experiments in the heat produced 

 in developing hydrogen from zinc and sulphuric acid. 

 The gas was passed through four wash-bottles before reach- 

 ing the gas-chamber, yet it might nevertheless have caused 

 an increase in the temperature in the gas-chamber. To 

 render this impossible or less possible the gas generator was 

 packed in a vessel with ice before beginning the experiment. 

 From this the hydrogen was led through a bottle filled 

 with chipped ice which was in turn again packed in ice. 

 The first three wash-bottles were also kept on ice. The 

 temperature of the last wash-bottle through which the 

 gas passed before reaching the gas-chamber was carefully 

 watched before and during the experiment. No increase 

 in temperature was noted when the hydrogen was passed 

 through it. 



The same water was used for the eggs in the gas-chamber 

 that was used for the control eggs. Every decrease in the 

 temperature of the latter through evaporation of the water 

 was carefully avoided, and their temperature carefully 

 watched. 



Cleavage in the eggs kept in the gas-chamber neverthe- 



